Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of a first image of a first embodiment in asequence for a display screen or portion thereof with transitionalgraphical user interface showing our new design;

FIG. 2 is a front view of a second image of the first embodimentthereof;

FIG. 3 is a front view of a third image of the first embodiment thereof;

FIG. 4 is a front view of a first image of a second embodiment thereof;

FIG. 5 is a front view of a second image of the second embodimentthereof; and,

FIG. 6 is a front view of a third image of the second embodimentthereof.

The broken line showing of a display screen or portion thereof withtransitional graphical user interface is included for the purpose ofillustrating portions of the article and forms no part of the claimeddesign.

CLAIM The ornamental design for a display screen or portion thereof withtransitional graphical user interface, as shown and described.